In conventional practice, curable silicone resin compositions are widely used as coating agents for providing the surfaces of various inorganic materials with water repellency or water resistance. Such silicone resin compositions for coatings use primarily polymethylsilsesquioxanes composed of siloxane units (hereinafter “T-units”) described by formula CH3SiO3/2, and methylsilicone resins composed of T-units and siloxane units (hereinafter “D-units”) described by formula (CH3)2SiO2/2. Such silicone resins are disadvantageous, however, in that the coating agent used for the base fails to provide adequate film hardness. Japanese Patent Application Publication (Kokai) No. Hei 2-8273 proposes a coating agent obtained by adding colloidal silica for use in forming high-hardness films. This agent, however, has inadequate storage stability and requires further improvement.
It is an object of the present invention to provide a silicone resin composition for a water-repellent coating that has excellent storage stability and is capable of forming high-hardness coating films with excellent water repellency when cured.